1. Field of the Invention PA1 2. Description of the Related Art
The present invention relates to a reinforcing bars binding machine which plays out a binding wire in a loop manner from a curved guide arm, winds it a plurality of times around the intersecting portions of reinforcing bars and, after then, twists part of the loop-wound portion of the binding wire to thereby tighten the wire and, in particular, to a safety device for use in such reinforcing bars binding machine.
Generally, in placing reinforced concrete on a building or a structure, after reinforcing bars which intersect each other crosswise are bound together with a wire, the concrete is placed. Recently, the reinforced concrete has been bound by use of a reinforcing bar binding machine. A reinforcing bars binding machine of this type is disclosed in Japanese Patent Application Laid-open No. Hei. 4-40686 which is applied by the present applicant. In this reinforcing bars binding machine, a main switch is previously turned on, when binding together the reinforcing bars, a trigger is pulled to thereby feed out a wire, the wire is played out in a loop manner from the leading end curved portion of a guide arm and is wound around the intersecting portions of reinforcing bars, and, after then, part of the loop-shaped portion the wire is hitched on a twisting hook and is then twisted and rotated to thereby tighten the wire so as to bind the reinforcing bars to each other efficiently.
In another reinforcing bars binding machine of this type, as disclosed in Japanese Utility Model Application Laid-open No. Hei. 5-3494 which is applied by the present applicant, after a wire is wound around the reinforcing bars in a loop manner, part of the loop-wound portion of the wire is held by a hook and is then rotated and twisted to thereby tighten the winding of the wire around the reinforcing bars, so that the reinforcing bars can be bound and fixed together strongly.
However, in the conventional reinforcing bars binding machines thus structured, if a main switch is previously on, then the binding machine is allowed to start automatically only by pulling a trigger, unexpected accidents can happen: for example, when an operator moves from one site to another with his or her fingers remaining put on the trigger, a wire can be fed out suddenly or a hook can be rotated suddenly to thereby hurt the operator, or as the result that the operator is surprised at such sudden wire feeding out or hook rotation, the operator can be hurt.